1. Field of the Invention
The present invention relates to an antenna apparatus which corresponds to plural frequency bands and a portable wireless device using the same.
2. Description of the Related Art
On a cellular phone as a major example of portable wireless devices used for mobile communication, installations of not only a function as a telephone but also communication system functions corresponding to various applications are proceeding As examples of such functions, FM radio reception, TV reception, a GPS function, compliance to Bluetooth standard, Wireless Local Area Network (WLAN) and the like can be cited. These systems differ from one another in frequency bands to be used and wireless circuitry, therefore, antenna elements corresponding to respective systems are required.
A structure of a portable wireless device including a conventional antenna apparatus is shown in FIG. 12. Portable wireless device 105 includes an antenna apparatus having first antenna element 101, second antenna element 102 and ground board 100. First antenna element 101 and second antenna element 102 are connected to ground board 100 respectively. First antenna element corresponds to a first system in a first frequency. Second antenna element 102 corresponds to a second system in a second frequency. Accordingly, the antenna apparatus corresponding to plural systems requires plural antenna elements corresponding to respective systems. Such conventional structure is disclosed in, for example, Japanese Patent Unexamined Publication No. 2002-237779.
However, in the conventional antenna apparatus, plural antenna elements are simply arranged in a ground board, therefore, when frequencies of antenna elements are close or overlapped, problems of property deterioration by a coupling between elements, and difficulty in adjusting the element itself by the coupling can occur.